Along with researchers from Texas A&M and SUNY-Buffalo, Old Dominion University economist Harry Zhang evaluated national obesity data for every county in the U.S. before, during and after the recession. They found that areas with higher unemployment rates also had higher obesity rates, and that the relationship was much more pronounced during the height of the recession in 2008-2009.

Looking at data from 2007 to 2011, the study noted a drop-off in the significance of the relationship as the economy recovered. "We found that the relationship between employment and the obesity risk was significantly reduced after the recession," said Zhang.

Cycle of stress, and few resources

Research shows that poverty, stress and depression are factors in both unemployment and obesity.

David Sarwer, director of clinical services at the Center for Weight and Eating Disorders at the University of Pennsylvania, said that stigma associated with obesity may also make it harder to find a job.

"Patients who are struggling with obesity, particularly struggling with extreme obesity, will report that they are stigmatized, if not outright discriminated against, in an employment setting," said Sarwer.

In the clinic, Sarwer also sees a relationship between job loss and weight gain. "Sometimes we'll see a major life event cause a significant weight gain in a short period of time, and one of the most common ones is the loss of a job."

In addition to psychological factors, Zhang mentioned crime rate, the availability of the Supplemental Nutritional Assistance Program (or food stamps), and poverty as other variables connecting the unemployment rate and obesity.

"We just looked at the two ends – local economic conditions and obesity risk. That's the two ends. But there should be many dots between them. This is why I'm advocating for more research to connect the dots," said Zhang.

He would also like policymakers to take what he has found and create more supports for the unemployed during future recessions. "In the next recession, the policymakers and local communities should be aware and do something to prevent people from gaining weight during recession time," Zhang said,

According to the Centers for Disease Control, more than one-third of adults in the U.S. are obese, and the cost of health care for people who are obese was $147 billion in 2008.